Feeding mechanism



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Aug. 22, 1961 M. .L FOX FEEDING MECHANISM 5 Sheets-Sheet 5 Filed NOV.20, 1957 United States Patent 2,997,297 FEEDING MECHANISM Merrill 5.Fox, Chicago, Iil., assignor to Bell & Howell Company, Chicago, Ill., acorporation of Illinois Filed Nov. 2t), 1957, Ser. No. 697,700 11Claims. (Cl. 271-57) This invention relates, generally, to feedingmechanisms and it has particular relation to mechanisms for feedingdocuments, such as checks, to recording apparatus, for example amicrofilm recording device.

Among the objects of this invention are: To provide means for sensingthe presence of a document being fed between feed and retard rollers ofa feeding mechanism in a new and improved manner; to employ a sensingroller for this purpose and to arrange for it to disconnect the drive tothe feed roller on the feeding of a document or documents having morethan a predetermined thickness; to automatically regurgitate thedocument or documents on the stopping of the feed roller; to drive theretard roller continuously and independently of the drive to the feedroller; to mount the sensing roller on a rockably mounted sensing lever;to provide a normally engaged electromagnetically controlled clutchbetween the feed roller and its driving means and to control theenergization of the electromagnetic means by a switch which iscontrolled by the sensing lever; to manually operate the sensing leverand thereby the switch to stop the feed roller and permit the retardroller to regurgitate a document or documents between it and the feedroller; to bias the sensing lever and thereby the sensing roller towardthe feed roller; to adjust the position of the switch relative to thesensing lever in order to vary the document thickness that can beaccommodated between the feed and sensing rollers; to mount the retardroller for bodily movement toward and away from the feed roller about anaxis spaced from its axis of rotation; and to provide for biasing theretard roller toward the feed roller and for adjusting the biasingaction to vary the pressure 'applied to a document or documents betweenthem.

Other objects of this invention will, in part, be obvious and in partappear hereinafter.

This invention is disclosed in the embodiment thereof shown in theaccompanying drawings and it comprises the features of construction,combination of elements and arrangement of parts that will beexemplified in the construction hereinafter set forth and the scope ofthe application of which will be indicated in the appended claims.

For a more complete understanding of the nature and scope of thisinvention reference can be had to the following detailed description,taken together with the accompanying drawings, in which:

FIGURE l is a top plan View of -a feeding mechanism constructed inaccordance with this invention, certain parts being broken away in orderto show more clearly the details of construction;

FIGURE 2 is a view, in front elevation, of the feeder shown in FIGURE 1;

FIGURE 3 is a vertical sectional view taken generally along the line 3 3of FIGURE 2;

FIGURE 4 `is a horizontal sectional view taken generally along the line4 4 of FIGURE 3;

FIGURE 5 is a sectional view taken generally along the line 5 5 ofFIGURE 3;

FIGURE 6 is a view in end elevation, taken generally in the direction ofthe arrows 6 6 of FIGURE 5 and showing a portion of a frame side memberand, by broken lines, the driving arrangement for the feed and retardshafts with the extension of the short shaft which is constantly drivenbeing shown in section; and

FIGURE 7 is a sectional view taken generally along the line 7 7 ofFIGURE 3.

Referring now particularly to FIGURE 1 of the drawings, it will beobserved that the reference character 10 designates, generally, a feederfor documents, such as checks, of the `general type shown in U.S. PatentNo. 2,652,248, issued September 15, 1953. The feeder 10` is intended forfeeding the documents to recording apparatus, such as microfilmrecording apparatus, and for this purpose it is desirable that thedocuments be fed one by one in order that matter appearing on both sidescan be recorded in a manner well understood.

The feeder 1t) includes vertically disposed frame side members 11 and 12which are positioned in parallel spaced relation and are interconnected,as shown in FIG- URE 3, by frame transverse members 13, 14 and 15 in theform of bars having a square cross section. Screws 16, extending throughthe frame side members 11 and 12 into the ends of the frame transversemembers 13, 14 and 15 serve to hold the assembly together and to providea rigid frame work on which the apparatus to be described is mounted. Atone end of the frame thus provided is a transverse plate 17 which issecured in position by screws 1S that extend into the frame transversemembers 13. Disposed between the frame side members 11 and 12 andsuitably secured thereto is a document support plate which is inclined,as shown in FIGURE 3, and is arranged to receive a stack of documents,such as checks, to be referred to presently. Positioned on the documentssupport plate 19 are `guides 22 having curved upper ends 23 whichoverlie similarly curved upper end portion 24 of the document supportplate 19. The guides 22 have upn standing walls 25 for receivingtherebetween the stack of documents 26, such as a stack of checks, whichare to be photographed on opposite sides. The guides 22 are adjustableon the document support plate 19 in order to accommodate different sizesof documents 26.V

The documents 26 move downwardly along the inclined document supportplate 19 underneath a lower curved port-ion 27 off a baille 28Whichextends between the frame side members 11 and 12 and is secured byscrews 29 to the frame transverse member 14. The lower curved portion 27has a slot 32 therein through which feed belts 33 carried by pulleys 34project. The feed belts 33 are circular in cross section and are formedof material such as rubber or rubber like material which have ygoodfrictional gripping engagement with the uppermost of the documents 26for feeding the same downwardly along the document support plate 19.

FIGURES 7 shows more clearly the mounting of the pulleys 34. It will beobserved that they are formed integrally with sleeve portions 35 havingbushings 36 at their ends for rotatable mounting on a shaft 37 which iscarried at the ends of arms 38 which are provided with bushings 39 forjournaling on a feed roller shaft 40. It will be understood that thearms 38 can rock about the axis of rotation of the feed roller shaft 40accompanied by bodily movement of pulleys 34 together with thoseportions of the feed belts 313 therearound. As shown in FIGURE 5 thefeed roller shaft 45 is journaled in bearing blocks 41 which are securedby screws 42 to the frame transverse member 14. A ring `43, secured byset screw 44 to the feed roller shaft 40, holds the latter againstendwise movement in one direction.

As shown in FIGURE 7 a friction feed roller, illustrated generally at46, is non-rotatably mounted on the feed roller shaft 40. The frictionfeed roller 46 includes integrally formed hubs 47 through which setscrews 4S project to secure the feed roller 46 non-rotatably to the feedroller shaft 40. Reduced diameter central sections 49 are formed on thefeed roller 46 around which the rubber feed belts 33 extend and wherebythey are driven on rotation of the feed roller 46.

The feed roller 46 also includes a large diameter central section S andlarge diameter end sections S1 all having a document engaging surface 52which has a relatively high coecient of friction. For example, thecoeilcient of friction of the document engaging surface 52 of thefriction feed roller 46 may be of the order of 1.0, the surface beingformed of a rubber like plastic material such as :PlastosoL 1t isdesirable to provide for controlling the rotation of the friction feedroller 46. For this purpose an electromagnetically controlled clutch,shown generally at 5-4, is employed and it is positioned, as shown inFIGURE 5, to control the driving connection between the feed rollershaft 40 and a driving member, shown generally at 55, in the form of agear 56. As will appear hereinafter provision is made for `continuouslydriving the gear 56.

Formed integrally with the gear S 6 is a sleeve 57 which is journaled inthe frame side member 11 and within which are bushings 5S in which thereduced diameter end portion :'59 of the feed roller shaft 40 isjournaled. Surrounding the reduced diameter portion 59 is a sleeve 60which is secured by a set screw 61 non-rotatably to the feed rollershaft 40. The external diameter of the sleeve 60 is the same as theexternal diameter of the sleeve 57 so that the surface of one issubstantially an extension of the surface of the other. A helical clutchspring 62 surrounds the sleeve 5-7 and the sleeve 60 and is so arrangedthat the convolutions thereof lightly grip the surfaces of thesesleeves. When the gear 56 is driven in the proper direction, theconvo-lutions of the helical clutch spring 62 more tightly grip thesurfaces of the sleeves 57 and 60 and drive the feed roller shaft 40 inthe direction by the arrow 63 to effect corresponding rotation of thefriction feed roller 46.

Provision is made for controlling the gripping action of the helicalclutch spring 62. For this purpose one end 64 of the spring 62 extendsinto an armature `65 in the form of an `annular magnetic member which isrotatably mounted on the sleeve 57 and is slidable endwise with respectthereto through a limited extent. Cooperating with the armature 65 is acoil 66 which may be connected by conductors 67 and 66 to a suitablecurrent source, such as a direct current source. The connection is madethrough a normally open switch 69 which is interposed in the conductor68. As will appear hereinafter provision is made for controlling theoperation of the switch 69 to effect closure thereof and energization ofthe coil 66 when it is desired to interrupt the driving connectionbetween the feed roller shaft 40 and the driving member 55. The magneticcircuit around the 'coil 66 includes a cylindrical core 70, an `annularend plate 71 and a cylindrical housing 72 which is provided with aradial ilange 7,3, FIGURE 2, that overlies a spacer 74 of nonmagneticmaterial. Screws 7S extend through the flange 713 and spacer 74 to mountthe cylindrical housing 72 and parts associated -therewith on the frameside member 11.

With a view to accelerating the disengaging action of the helical clutchspring from the sleeves 57 and 60, the other end 76 of the spring 62extends into a flywheel 77 which is rotatable on the sleeve 60. Theinertia of the flywheel 77 is effective to release the Igrippingengagement between the convolutions of the helical clutch spring 62 onenergization of the coil y'66 in the manner described in more detail incopending application Serial No. 689,- S62, filed .October 14, 1957, nowabandoned, and assigned to the assignee on this application.

Cooperating with the friction feed roller 46, as shown more clearly inFIGURE 5 of the drawings, is a retard roller S0. The retard roller 80 isarranged to rotate in the same direction as the direction in which thefeed roller 46 rotates for the purpose of permitting the documents 26 tobe fed singly by the feed roller 46.

The retard roller is provided with hubs S1 formed integrally therewiththrough which set screws 82 extend for non-rotatably securing the retardroller 80 to a retard shaft 33. The retard shaft S3 extends transverselythrough slots 84 in cylindrical bearing supponts 8S which have integralflanges 86 that are secured by screws S7 to a bearing support plate S8.As shown in FIGURE 3, the bearing support plate 88 is secured by screws89 to a transverse shaft 90 which may have a square cross section. Thetransverse shaft 90 is rockably mounted between the frame side members11 and 12 by means of pivot screws 91, FIGURE 4, which have cylindricalbearing portions 92 that are journaled in suitable openings in the frameside members 11. The manner in which the bearing support plate 88 iscontrolled for positioning the retard roller 80 with respect to the feedroller 46 will be described hereinafter.

Referring again to FIGURE 5 of the drawings it will be observed thatintermediate sections 93 of the retard roller 80 are positioned oppositethe large diameter end sections 51 of the friction feed roller 46. Inaddition routboard sections 94 lare formed integrally with the retardroller S0. It will be observed that an aperture 95 is provided in thebearing support plate 83 through which the sections 93 and 94 of theretard roller 80 project. Apertures 96 and 97 are provided in thedocument support plate 19 for receiving therethrough the sections 93 and94 of the retard roller 80. The surfaces 99 of the sections 93 and 94 oflthe retard roller 80 have a relatively low coeicient of friction ascompared to the coefficient of friction of 'the surface 52 of thefriction feed roller 46. For example the coefficient of friction of thesurface 99 may be of the order 0.707 and may be formed by suitablerubber like material having such a coeicient of friction such -asPlastosol or polyvinyl chloride. The reason for employing materialshaving different coecients of friction is set forth in detail incopending application Serial No. 700,171, led December 2, 1957, andassigned to fthe assignee of this application.

It is desirable to maintain the spacing shown at 102 in FIGURE 5 betweenthe document engaging surfaces 52 and 99 of the feed roller 46 andretard roller 80 even though these surfaces may wear from continued use.One manner of accomplishing this is disclosed in more detail in thecopending application just referred to. Such means include bear-ings 103that are slidably mounted in the cylindrical bearing supports 85 inwhich the retard shaft S3 is journaled. Coil compression springs 104react between the bearings 103 and screw caps 10S that are threaded intothe cylindrical bearing supports 85. The springs 104 bias the retardshaft S3 and thereby the retard roller 80 toward the feed roller 46. Thesprings 104 also bias the retard shaft `83 against wear shoes 106 thatare circular in cross section and are shaped to bear against the retardshaft 83 for a limited arcuate extent. The wear shoes 106 projectthrough openings l107 in the bearings 103 and are provided with threadedextensions 108 that are screwed into base portions 109 of thecylindrical bearing supports 85. The wear shoes 106 are so characterizedthat they wear away at a rate ycorresponding to the rate `at which thesurfaces 52 and 99 of the feed roller 46 and retard roller 80 wear away.As this wear takes place and the wear shoes 106 are reduced in thicknessthe spacing 102 remains constant.

It will be recalled that the retard roller 80 is rotated in the samedirection as the direction, indicated by the arrow 63, in which the feedroller 46 is rotated. Specifically provision is made for rotating theretard shaft 83 in the direction indicated by the arrow 110 through theagency of a flexible shaft 111 which is connected to a short shaft 112that is journaled in bearing bushings 113 that are carried by a sleevei114 which is threaded in the frame side member 11. It will be lobservedthat the short shaft 112 is rotatable about an axis that is xed in spacewhile the retard shaft 83 is rotatable about an axis which is movablerelative to the xed axis of rotation of the short shaft 112. The retardshaft 83 is movable not only as the result of movement of the bearingsupport plate 88 but also its axis of rotation shifts slightly as thewear shoes 196 wear and the retard shaft 80 is moved toward the feedroller shaft 40 under the inuence of the springs 104.

As shown in FIGURE 5 the short shaft 112 is provided with an extension115 that projects beyond the frame side member 11 and is connected tosuitable driving mechanism, such as the drive mechanism for themicrofilm recorder, for rotating it constantly in the directionindicated by the arrow 110 while the mechanism is in operation.

FIGURE 6 shows the driving connection between the extension 115 and thefeed roller shaft 40. It will be observed that a gear 116 is fast on theextension 115 and that it meshes with an idler gear 117 which isjournaled at 118 on the frame side member 11. It will be observed thatthe idler gear 117 meshes with the gear 56 and that these gears arelocated in a triangularly shaped recess '119 which is formed in theouter side of the frame side member 11. A cover plate 120 overlies therecess 119 and parts disposed therein and is secured by screws 121 tothe frame side member 11.

Referring now to FIGURE 3 of the drawings it will be observed that thebearing support plate 88 has an integrally formed extension 124 whichalso is shown in FIGURE 4. The sides of the extension 24 are inclinedfrom the support plate 88 toward a bifurcated end 125 having a slot 126in which a threaded stud 127 that stands upwardly from the frametransverse member 13 extends. The position of the bifurcated end 125 ofthe extension 124 can be varied by a thumb nut 128 which is threaded onthe stud 127. A coil compression spring 129 reacts between the undersideof a thumb nut 130, also threaded on the stud 127, and the upper side ofthe bifurcated end 125. By adjusting the thumb nut 130, the tensionapplied by the spring 129 to the extension 124 can be varied for varyingthe pressure that is applied by the retard roller 811 in the directionof the feed roller 46 and against the document or documents that mayappear therebetween. A holding spring 131 is interposed between locknuts 132, threaded on the stud 127, and the thumb nut 130 formaintaining it in any position to which it may be adjusted.

The presence of two or more documents or of a document of unusualthickness appearing between the feed roller 46 and retard roller 80 isdetected by a sensing roller 135, FIGURES 3 and 4, which is journaled ona shaft 136 that extends between arms 137 of a sensing lever 138. Thesensing lever 138 is rockably mounted on a shaft 139 which is journaledin bearing brackets 140 which are secured by screws 141 to the frametransverse member 15. A torsion spring 142 reacts against the sensinglever 138 to bias it in the direction indicated by the arrow 143, FIGURE3, to cause the sensing roller 135 to engage the large diameter centralsection 50 of the friction feed roller 46. The sensing lever 138 has achannel shaped extension 144, FIGURES 3 and 5, and at its outer endthere is a at portion 145 which engages a plunger 146 of the normallyopen switch 69. The switch 69 includes a spring 147 which normallybiases the plunger 146 to close the switch contacts. They are held openagainst the biasing action of the spring 147 by the at portion 145 0fthe sensing lever 138 which is held in position by the torsion spring142. The spring 147 which biases the plunger 146 is illustrateddiagrammatically in FIGURE 5. The flat portion 145 of the sensing lever138 continues to an offset portion 148 which extends through an aperture149 in the transverse plate 17. By manually depressing the offsetportion 148 of the sensing lever 138 in the direction indicated by thearrow 150, the plunger 146 of the switch 69 is relieved and the spring147 is free to close the contacts of th switch 69 for energizing thecoil 66 to disconnect the driving connection between the driving member55 and the feed shaft 4t) for stopping further feeding of the documentsby the feed roller 46. Since the retard roller continues to rotate whenthe feed roller 46 is stopped, the document or documents therebetweenare regurgitated. With a View to permitting adjustment of the positionof the switch 69, FIGURE 3, it is mounted on an arm 152 which isrockably mounted on a shaft 153 that is carried by a bracket 154. Thebracket 154 extendsl forwardly and upwardly from the frame transversemember 13 and is secured thereto by screws 155. The arm 152 vhas arearward extension 156 which overlies a thumb nut 157 that is threadedon the stud 127. By varying the position of the thumb nut 157, acorresponding change is effected in the position of the arm 152 andthereby of the switch 69. A handle 159 extends rearwardly from theextension 156 and it is biased downwardly by a spring 160 that surroundsthe stud 127 and is located underneath the thumb nut 128.

When it is desired to feed a document or documents having a thicknessgreater than normal, the operator can manually grasp the handle 159 andapply an upward force thereto as indicated by the arrow 161 to preventclosure of the contacts of the switch 69 by the downward swingingmovement of the sensing lever 138 in response to movement of the sensingroller 135 as the result of the insertion between it and the feed roller46 of the abnormal documents thickness.

In operation, provision is made for constantly rotating the extension ofthe short shaft 112 and thereby causing rotation of the retard roller 80in the direction indicated by the arrow 162 on FIGURE 3 of the drawings.At the same time, since the coil 66 of the electromagnetic clutch 54 isdeenergized, the feed roller shaft 40 rotates to drive the feed roller46 in the direction indicated by the arrow 163, FIGURE 3. The documents26 are fed singly by the feed roller 46 and they pass between it and thesensing roller 135. As long as the document thickness does not exceedthat for which the mechanism is set, the documents 26 continue to be fedone by one to the mircolm recording apparatus or other apparatus as thecase may be.

Should a document having an extra thickness or two documents be fedbetween the feed roller 46 and the sensing roller 135, the latter ismoved further away from the former and the sensing lever 138 is rockedin a counterclockwise direction against the biasing action of thetorsion spring 142. The plunger 146 then moves downwardly under theinfluence of the spring 147, FIG- URE 5, and contacts of the switch 69are closed. Coil 66 is energized and, in the manner hereinbeforedescribed, the clutch spring 62 is caused to release its grippingengagement with the sleeves 57 and 60. The feed roller shaft 40 and feedroller 46 promptly stop. Since the retard roller 80 continues to rotatein the direction indicated by the arrow 162, FIGURE 3, the document ordocuments are regurgitated and the sensing roller is again biased towardthe feed roller 46. The contacts of the switch 69 are opened and coil 66is deenergized. Thereupon the clutch 54 is operated to restore thedriving connection between the driving member 55 and the feed rollershaft 40 and the operation resumed.

Should it be desired to regurgitate the document or documents manually,the offset portion 148 of the sensing lever 138 is depressed in thedirection indicated by the arrow and the sequence of operation justdescribed is effected to stop the feed roller 46 and permit the retardroller 80 to regurgitate the document or documents.

Since certain further changes can be made in the foregoing constructionand different embodiments of the invention can be made without departingfrom the spirit and scope thereof, it is intended that all matter shownin the accompanying drawings and described hereinbefore shall beinterpreted as illustrative and not in a limiting sense.

What is claimed as new is:

l. In a document feeding mechanism, in combination, a rotatable feedroller having a document engaging surface positioned to continuouslyengage and trictionally feed documents from a stack to recordingapparatus, a retard roller in opposed relation to said feed roller androtated continuously in the same direction as said feed roller andhaving a document engaging surface to continuously engage and cause saiddocuments to be fed singly by said feed roller, driving means for saidfeed and retard rollers, normally engaged clutch means between saiddriving means and said feed roller for controlling the drivingconnection therebetween, and means for disengaging said clutch means tostop said feed roller and permit regurgitation of said documents by saidretard roller.

2. In a document feeding mechanism, in combination, a rotatable feedroller having a document engaging surface lpositioned to continuouslyengage and frictionally feed documents from a stack to recordingapparatus, a retard roller in opposed relation to said feed roller androtatable in the same direction as that of said feed roller and having adocument engaging surface to continuously engage and cause saiddocuments to be fed singly by said feed roller, driving means normallyoperable to rotate said feed and retard rollers in the same direction,normally engaged clutch means between said driving means and said feedroller for controlling the driving connection therebetween, and meansresponsive to the feeding of two or more documents by said feed rollerfor disengaging said clutch means to stop said feed roller and permitregurgitation of said documents by said retard roller.

3. In a document feeding mechanism in combination, a cylindrical feedroller rotatable on the longitudinal axis thereof and having a documentengaging surface positioned to continuously engage and frictionally feeddocuments from a stack to recording apparatus, a retard roller inopposed relation to said feed roller and rotatable in the same directionas that of said feed roller and havmg a document engaging surface tocause said documents to be fed singly by said feed roller, driving meansno1'- mally operable to rotate said feed and retard rollers in the samedirection, normally engaged clutch means between said driving means andsaid feed roller for controlling the driving connection therebetween, asensing roller biased toward said feed roller for receiving documentstherebetween, and means responsive to predetermined movement of saidsensing roller away from said feed roller in response to appearancetherebetween of two or more documents for disengaging said clutch meansto stop said feed roller and permit regurgitation of said documents bysaid retard roller.

4. In a document feeding mechanism, in combination, a rotatable feedroller having a document engaging surface positioned to continuouslyengage and frictionally feed documents from a stack to recordingapparatus, a retard roller in opposed relation to said feed roller androtatable in the same direction as said feed roller and having adocument engaging surface to continuously engage and cause saiddocuments to be fed singly by said feed roller, driving means for saidfeed and retard rollers, normally engaged clutch means between saiddriving means and said feed roller for controlling the drivingconnection therebetween, electromagnetic means when energizeddisengaging said clutch means, a sensing roller in operative relation tosaid feed roller for receiving documents therebetween, a sensing levercarrying said sensing roller, means rockably mounting said sensing leverand biasing the same and thereby said sensing roller toward said feedroller, switch means connected to said electromagnetic means andcontrolled by said sensing lever whereby it is responsive topredetermined movement of said sensing roller away from said feed rollerin response Ito appearance therebetween of two or more documents fordeenergizing said electromagnetic means and disengaging said clutchmeans to stop said feed roller and permit regurgitation of saiddocuments by said retard roller, and manual means for operating saidswitch means to deenergize said electromagnetic means and disengage saidclutch means to stop said feed roller and permit regurgitation of saiddocuments by said retard roller.

S. In a document feeding mechanism, in combination, a rotatable feedroller having a document engaging surface positioned to continuouslyengage and frictionally feed documents from a stack to recordingapparatus, a retard roller in opposed relation to said feed roller androtatable in the same direction as said feed roller and having adocument engaging surface to continuously engage and cause saiddocuments to be fed singly by said feed roller, driving means for saidfeed roller, normally engaged clutch means between said driving meansand said feed roller for controlling the driving connectiontherebetween, electromagnetic means when energized disengaging saidclutch means, a sensing roller in operative relation to said feed rollerfor receiving the documents therebetween, a sensing lever carrying saidsensing roller, means rockably mounting said sensing lever and biasingthe same and thereby said sensing roller toward said feed roller, switchmeans connected to said electromagnetic means and controlled by saidsensing lever whereby it is responsive to predetermined movement of saidsensing roller away from said feed roller for deenergizing saidelectromagnetic means and disengaging said clutch means, means rockablymounting said switch means in operative relation to said sensing lever,and means for adjusting the position of said switch mounting means tovary the document thickness that can be accommodated between said feedand sensing rollers without effecting switch operation to stop said feedroller.

6. In a document feeding mechanism, in combination, a rotatable feedroller having a document engaging surface positioned to continuouslyengage and frictionally feed documents from a stack to recordingapparatus, a retard roller in opposed relation to said feed roller androtatable in the same direction as said feed roller and having adocument engaging surface to continuously engage and cause saiddocuments to be fed singly by said feed roller, driving means for saidfeed roller, normally engaged clutch means between said driving meansand said feed roller for controlling the driving connectiontherebetween, electromagnetic means when energized disengaging saidclutch means, a sensing roller in operative relation to said feed rollerfor receiving the documents therebetween, a sensing lever carrying saidsensing roller, means rockably mounting said sensing lever and biasingthe same and thereby said sensing roller toward said feed roller, switchmeans connected to said electromagnetic means and controlled by saidsensing lever whereby it is responsive to predetermined movement of saidsensing roller away from said feed roller for deenergizing saidelectromagnetic means and disengaging said clutch means, means rockablymounting said switch means in operative relation to said sensing lever,and manually operable means connected to said switch mounting means forrendering said switch means inoperative to deenergize saidelectromagnetic means and permit the feeding of documents having agreater than normal thickness.

7. In a document feeding mechanism, in combination, a rotatable feedroller having a document engaging surface positioned to frictionallyfeed documents from a stack to recording apparatus, a retard roller inopposed relation to said feed roller and rotatable in the same directionas said feed roller and having a document engaging surface to cause saiddocuments to be fed singly by said feed roller, a retard shaft carryingsaid retard roller and rotatable therewith, a support plate on whichsaid retard shaft is journaled, means rockably mounting said supportplate about an axis offset from and parallel to the axis of rotation ofsaid retard shaft, means biasing said support plate and thereby saidretard roller toward said feed roller, driving means for said feedroller, normally engaged clutch means between said driving means andsaid feed roller for controlling the driving connection therebetween, ashort shaft iournaled to rotate about an axis fixed in space relative tosaid axis of rotation of said retard shaft and disposed in generalendwise relation with respect thereto, a exible shaft interconnectingsaid retard shaft and said short shaft, means for driving said shortshaft, a sensing roller biased toward said feed roller for receivingdocuments therebetween, and means responsive to predetermined movementof said sensing roller away from said feed roller in response toappearance therebetween of two or more documents for disengaging saidclutch means to stop said feed roller and permit regurgitation of saiddocuments by said retard roller.

8. In a document feeding mechanism, in combination, a rotatable feedroller having a document engaging surface positioned to frictionallyfeed documents from a stack to recording apparatus, a retard roller inopposed relation to said feed roller and rotatable in the same directionas said feed roller and having a document engaging surface to cause saiddocuments to be fed singly by said feed roller, a retard shaft carryingsaid retard roller and rotatable therewith, a support plate on whichsaid retard shaft is journaled, means rockably mounting said supportplate about an axis offset from and parallel to the axis of rotation ofsaid retard shaft, means biasing said support plate and .thereby saidretard roller toward said feed roller, means for adjusting said biasingmeans to vary the pressure applied by said retard roller in thedirection of said feed roller, driving means for said feed roller,normally engaged clutch means between said driving means and said feedroller for controlling the driving connection therebetween, a shortshaft journaled to rotate about an axis fixed in space relative to saidaxis of rotation of said retard shaft and disposed in general endwiserelation with respect thereto, a flexible shaft interconnecting saidretard shaft and said short shaft, means for driving said short shaft, asensing roller biased toward said feed roller for receiving documentstherebetween, and means responsive to predetermined movement of saidsensing roller away from said feed roller in response to appearancetherebetween of two or more documents for disengaging said clutch meansto stop said feed roller anld permit regurgitation of said documents bysaid retard ro er.

9. In a document feeding mechanism, a cylindrical feed roller mountedrotatably on a predetermined axis, at the center thereof, a retardroller, means urging the retard roller toward the feed roller intocontinuous engagement with a sheet and hold the sheet against the feedroller and permitting movement of the retard roller away from the feedroller, a justable stop means limiting movement of the retard rollertoward the feed roller, means for rotating the feed roller in adirection such as to advance the sheet between the rollers, means forcontinuously rotating the retard roller in a direction tending toadvance the sheet from between the rollers, and means responsive to feedof more than one sheet for stopping the feed roller rotating means.

10. In a document feeding mechanism, means for supporting a stack ofdocuments, feed means continuously engaging the top document, firstdrive means driving the feed means so as to feed the top document in aforward direction, retard roller means mounted rotatably in a positionopposed to the feed means for continuously engaging the document, seconddrive means driving the retard roller means continuously in a directiontending to prevent documents below the top document from being advancedwith the top document, means urging the retard roller means toward thefeed means, means limiting movement of the retard roller means towardthe feed means, Iand means responsive to the presence of more than onedocument between the feed means and the retard roller means forrendering the rst drive means inoperative.

11. In a document feeding mechanism, forward feed means for continuouslyengaging a document and feeding the document forwardly, retard feedmeans in opposed relationship with the forward feed means forcontinuously engaging yand feeding a document rearwardly, sensing meansfor detecting the presence of more than one document between the forwardfeed means and the retard feed means and responsive thereto forrendering the forward feed means inoperative, and selectively operablemeans for rendering the sensing means operative and inoperative.

References Cited in the le of this patent UNITED STATES PATENTS 584,073Dexter June 8, 1897 1,701,861 Niblack Feb. 12, 1929 2,224,137 Breman etal Dec. 10, 1940 2,670,954 Bach Mar. 2, 1954 2,836,416 Van Marle May 27,1958

